FORGERS’ CHIEF ENEMY.

Hauraki Plains Gazette, Volume XXXVI, Issue 4819, 6 March 1925, Page 4

FORGERS’ CHIEF ENEMY.

CHEMIST AND HIS TEST TUBE-

By

R. G. Nicholls.)

In the detection of forgery the expert in handwriting is generally given the chief honour, but actually the skill of this expert is applicable in a few cases only, and even in these his evidence is unreliable outside certain narrow limits. The skill of the chemist, on the other hand/is capable of far wider application, and his evidence is definitely reliable, being .the result of reasoning based on scientific facts.

When a suspected document is alleged to be old, the composition of the paper sometimes offers very complete evidence of forgery. For instance, it is obvious that a document is forged when it is written on paper made from wood pulp and yet bears a date long before wood pulp was used for making paper.

The ink used for writing a docu-

ment provides much more evidence than the paper it is written .on. To some extent the composition of the ink'-dates a manuscript. Ctirbon ink—made of lampblack or soot suspended in gum—wats used in ancient Egypt and is still used .to-day as Indian ink; but it was discarded, for ordinary uses, by the middle of the fourteenth century in favour of ink made from iron sulphate and extract of galls. .about sixty years ago various coaltar dyes began to be used for making "inks, and liow the plain iron gall ink is in small demand.

.in the Menzies case documents bearing dates from 1719 to 1772, brought forward in support of a, peerage claim, were alleged to have been altered. The chemist consulted proved that the ink used- for making the alleged alterations was different in composition from that used for the remainder of the document. Atfd this was not all, for the chemist was also able to show that the alterations had been made with a steel pen. And as stee] pens were not invented until 1808, 90 years after the date of the docu-

ment, forgery was evident. - In the Pilcher case the validity of a will dated 1898-was disputed. When tested the ink was found to react immediately with the chemicals used ; but the ink on the testator’s cheques dated 1904 to 1906 gave only a very slow and slight reaction, while the ink on cheques dated 1902 gave no reaction at all. The evidence supplied by these and other tests was sufficient to prove that the will was not written in 1898, but at least six years after that date.— ‘Daily Mail.”